hello and welcome to HCM, I am Dr Sriram Nathan an ENT surgeon who has treated thousands with throat problems over the years and I will try to help you out with your problem. At the offset let me assure you that it may just be an reflux or a mild recovering infection which can cause blood in the sputum. The blood may originate from either the throat due to infection or the mucosa of the stomach due to reflux which in turn can be due to stress and medication. Do not worry as it is very common and you will get better in a week or two. Since you have also done all the tests and they are normal you further have nothing to worry about. In any case you need to relax and do these immediately: -Start an anti reflux tablet like pantoprazole along with a multivitamin like the zincovit. These will help your throat to be resistant to irritation and also keep the reflux and blood under check. Your doctor will know about these medications. -continue your antibiotic medication without fail -Avoid anything spicy, oily or high flavoured -Take only bland non oily and non spicy diet with lots of green leafy vegetables for the next one week Wait for a week if your bleeding does not stop then you must take an endoscopy of the upper GI get back to any ENT surgeon with the reports. Take care regards Dr Sriram Nathan